Sunday, August 12, 2012

Planning to find Ceres

Last day of my summer vacation... Yesterday I was out rollerblading at 22-23 and it really started to get dark. Closer to midsummer that was the best time since it wasn't so hot anymore, but now, note to self, better go a bit earlier.

Anyways the darkess made me start planning future observations. Some time ago, might have been while watching Venus transition (btw I think I should blog about that as well even though it was months ago) I started thinking if it were possible to see dwarf planet Ceres with my telescope. Checking Wikipedia about Ceres tells me that its magnitude ranges from 6.7 to 9.3. Being still such a beginner at this, I really don't know if that's something I can see from my backyard.

I had taken photos of Orion's sword and Pleiades with Canon SX 200 IS, which is a compact camera with 60mm (or 12x) zoom. The photos were taken with exposure time of 1 and 2 seconds (on a tripod without tracking), 40 shots and then combined with DeepSkyStacker. I compared the photos with star charts (Stellarium) to see how faint magnitudes can be seen where I observe. Here's an example of Pleiades:

Pleiades with a few apparent magnitudes of visible stars.
So... The brightest star on Pleiades is 2.85. There are several stars of approximately magnitude 7. I could even see stars with magnitudes of 10 and 11.25 (according to Stellarium). I'm a little sceptical about that 11.25, but 10 seems reasonable.

For now it looks like it is possible to see Ceres. Nowadays I have better optics (Canon EOS 1100D and max 300mm zoom) and a tracking mount (EQ3-2). And of course I'd like to have a visual observation rather than a photo. First I'm going to find the dwarf planet on camera, then try to see it through a telescope.